I use tomato. You can boost to 251mW so it should serve your purpose, and tomato has a very nice, easy to use interface.
If you dont want tomato, Instead of DD-WRT I suggest OPEN-WRT. I won't use DD-WRT beacuse of issues in the past with regards to the integrity of the "developer".
http://en.wikipedia.org/wiki/DD-WRT#Controversy
More info can be found online if you are curious, but the guy is basically a doucher.
Thing is, if he has a Linksys WRT54G v6, I don't think loading either Tomato or OpenWRT is supported due to both the VxWorks and small NVRAM of 2MB, where a DD-WRT is supported. So DD-WRT might be the only game in town for that router, as it was for my Linksys travel router.
You want controversy, check out Sveasoft. I was once a subscriber for a couple of years. There must have been more controversy around that than DD-WRT, and of course some of the controversy involves all three. Sveasoft referring to DD-WRT as a "Sveasoft fork", which is true as it started as a fork of Sveasoft Alchemy, but that was quite a while back. And of course, OpenWRT openly accused Sveasoft of violating GPL. I found an article at
Wi-Fi Planet about the whole sordid incestuous mess.
Even though there are seemingly some violations, even the violators perhaps still deserve some credit for helping create viable 3rd party firmware for these routers.
Sveasoft whatever you think of them, played a big role in starting it all, at least that's how I got into it.
DD-WRT picked up offering a free fork as Sveasoft moved more & more towards copy protection and no free versions. Say what you might about DD-WRT, they still offer a free version that works fine for many and on hardware sometimes not supported by other projects.
OpenWRT I believe came after those and doesn't have that "taint" to my knowledge. Many folks like it, and I have run it before. Generally thought of as geared towards more advanced users. Has some offshoots like X-WRT, FreeWRT, and Gargoyle.
HyperWRT came out around the same time and I became a fan for the commitment to minimal changes to the Linksys base for stability sake. When Timothy Jans gave up working on HyperWRT, a couple of other developers took it over with two forks, thibor and tofu. They collaborated a lot and eventually the HyperWRT+Tofu (Jon Zarate) developer folded his code into HyperWRT+Thibor and brought out Tomato which I have also been a big fan of although it runs on relatively few routers compared to OpenWRT or especially DD-WRT. Tomato has various offshoots/"mods" including, but not limited to, roadkill, TomatoVPN, Teddy Bear(aka USB), Thor, Trzepak, Victek Tomato RAF. These add features such as OpenVPN, USB support, SD card support, etc. (see
table here).
There are
other projects, but those are the bigs ones, at least from my perspective.
Anyway, I'm going off, I better stop, for now....