I got a cheap Solarforce host that takes 18650's for 8 bucks on the marketplace. It seemed like a good deal but I dont think its worth it. First off my Malkoff dropins dont make a connection when using a real surefire bezel and tailcap. Apparently I need to do some kind of spring extention on the bottom of it or something. Either way this seems like its not very reliable. Secondly, to my shock, when I was trying to find a solution the other day I put an oring in with the M61, on the lens side of the bezel. My thinking being that it would push the dropin a few mm's back towards the batteries and thus make contact. Well it worked. Unfortunately when I went to take the bezel off, I had hand tightened it too much. The Solarfoce host separated into two different parts. I had no idea this could happen and it freaked me out pretty good. Upon examining however I guess its normal... However when I put the z44 bezel back on, and just lightly hand tightened it, after I had tightly hand tightened the Solarforce body back together, it still got stuck in the bezel. This might be confusing so I will add some pics. Either way, go to the marketplace and grab a bored 6P for 64 bucks or a bored c2 for like 90. They have c2s on clearance right now at lapolice gear for 54 plus shipping (10) so about 64 total, unbored. You could always find a member to bore it for around 25 bucks but probably worth it to just buy the bored host in the first place. I dont know. Its alot of money for a surefire bored host, but its of very high quality. You're other option of course is to get a different host. Malkoff makes some awesome hosts that come standard with 18 mm diameters. With those you can also add a hi/lo ring and run a dropin in low mode for lot longer. They however only take Malkoff drop ins.
I tried going the cheap route at first but just found it was too frustrating. I also value reliability and service, two things that come with a price tag. When I first got into this game I remember a guy saying, eventually you'll have all nice stuff, so you might as well save yourself the headaches and money and just buy it off the bat. I wish I had. I've since flipped all the cheaper stuff I bought and now just stick with a few quality hosts, and my Malkoff dropins and am pretty happy with them.
Im also not so sure how easy it is to just 'sand down' a Surefire host. If you have the knowledge or have done it before then by all means, my mistake. Ive seen how members on here bore hosts and there's alot more to it than just throwing some sand paper in there. They usually have pretty complex computerized lathe systems that leave retention lips in the hosts so the batteries remain. Anyways if you need more advice youve come to the right place. In the end though its just about what youre willing to spend. And just know, I was here a year ago and hadn't spent a dime, and now Im in over $3500. Its ok though, you can always sell stuff on the MP.