Noticed ITC-Shop on Ebay is having a sale of Solarforce bodies & tubes.
Complete bodies (head, tube, and tailcap/switch) are going for $10.56 with free shipping; supposedly the sale lasts 3 more days. I do think these are lower than regular prices. My apologies if not. This is about $4 more than just the battery tube alone.
Only black available on all sale items :(
Solarforce L2i BLACK AAA battery flashlight body
Solarforce L2r BLACK AA Battery flashlight Body
These are among the very few AAA and AA P60-compatible hosts out there, and the most respectable. It seems to me the tubes all fit into the same head. Looks like the L2 switch works on the L2r (AA version) (not confirmed), and of course the AAA version comes with its own switch due to its width (I'd like to know if that switch works on other 3 x AAA lights).
If you just want the tubes, they're currently only $6.29 with free shipping. You can play like Legos. The AAA version comes with the adapter/battery holder.
Solarforce AAA x 3 Battery tube for Surefire 6P 9P
Solarforce AA x 2 Battery tube for Surefire 6P 9P
The normal 18650 L2 hosts don't seem to be on sale; ITC is selling them for $12.63 with free shipping, which is still a great deal for such a nicely made host. Lighthound however sells them from Texas (much faster shipping and probably better support) for not much more, around $13 with low shipping fees and a large of selection of other things. I guess what's different currently about ITC's L2's is they're selling non-black versions at the same low price; a few weeks back, Lighthound actually had the best deal on non-black finishes.
My interest in these was partly due to (or "justified by") 'preparedness'--the concept of having a decent flashlight which could use 'standard' alkaline cells. That, as well as they'd make great hosts for a gift, if you have a drop-in which is fine, but obsolete in your collection due to upgrades, yet would be a step up for a non-flashaholic friend. In the end, I justified paying the extra $4 per flashlight to get the complete body.
Solarforce-shop sells a 'kit' which includes one head, and 3 bodies (18650, AA, and AAA) for $20 plus shipping. Especially if you already have an L2 or L2m, the above links are better deals, which makes me think it is really a sale.
To newbies playing catch-up: obviously don't expect the 2 x AA version to light up every drop-in on two alkaline batteries or NiMH rechargeables. You can get 'low voltage' Solarforce-branded drop-ins from Lighthound and Solarforce, and I'm not sure how other common drop-ins fare with 3.0 volts. The (now mostly unavailable) NiZn from Powergenix would be a good choice, or have a multi-voltage drop-in and use two 14500's in either the very safe LiFePO4 chemistry (peak charge 3.6 to 3.8 volts per cell, depending on how abusively you charge them) or two LiCo (standard lithium ion) 14500's. I saw LiFePO4 14500's cheap at Kaidomain.com. LiCo 14500's are widely available but charge to 4.2 volts so 8.4 volts with two. Be warned the bezels on these are sharp and annoying. You can buy smooth bezels, or just screw the sharp bezel off and use the light without a glass lens; you'll just obviously inevitably get some dirt and dust in the reflector at some point (a bigger deal for smooth reflectors, if you ask me). Lighthound sells the smooth bezels for $3 plus shipping, ITC on Ebay is pricey at $5 shipped. I was able to use a smooth bezel from an Ultrafire 504b. The 504b's are nice too--they don't feel as high quality, but are very passable if not quite as Surefire-compatible as the Solarforces. I have interchanged heads, and some switches. You won't get the same level of compatibility with other-branded models like 501b, 502b, and 503b. The L2 series and 504b are copies or take-offs of the venerable American-made Surefire 6P flashlight, which despite a good design and supposedly peerless manufacturing, Surefire (like Mag Industries/Mag Light) did not do a good job of keeping up with the LED revolution (from incandescents). Surefire still focuses on multi-cell 3.0V primary CR123 tubes (I think the "6" in 6P stands for 6 volts, meaning the 2-cell version), which to you means that 18650's can't fit into them (although 17670's can). I think Solarforce originally specialized in selling accessories for Surefire owners (such as 18650-compatible tubes), but their own variants have taken on a life of their own. Many, including myself, consider them to be the best (and most Surefire-compatible) budget P60 hosts.