I have on all my other bikes. The only time I've ever had a problem with a filter was when it was physically resting against the exhaust tubes. Outside of that, if you put them close to the carbs (where they should be anyways to catch anything that breaks loose from the fuel tubes themselves) they should stay cool enough. I'd say cut about 1" away from connection to carbs and install inline filter there, unless you were planning on linking the two banks.

I can't remember where but I sourced some really nice aluminium sheathed ones with replaceable filters, but even still, they were only like $7.

In any case, a filter won't have problems with the heat from under the bike unless you're doing something really radical in terms of cooling or are already on fire (not recommended).

I actually have been having problems with a sticking float so I was actually going to source some and install them next weekend. It's usually good practice to have them on any fuel system regardless of application.