The SPG is very popular as a 4 weight, but I would never talk anyone out of "overlining" by one weight. (And for those of you who want to cast better, try overlining before you think it's necessary to spen $75-100 for a new fly line that won't help much anyway.)

For an inexpensive "close in" rod to build, consider a 7'6" 4 weight -- and use a lower modulus graphite. It'll be much lighter than the glass blank and, in my opinion, easier to cast for long periods of time. Mod-fast graphite won't cost that much -- ask Brad and he'll tell you who to call!