Keith,
you mentioned fishing medium to small streams , get a rod of 7'6" in a 4/5 weight , if you want to nymph you can always use dry dropper with this setup and clobber the fish.Itss kinda hard with overhead and no back room to nymph with a longer rod, if you are doing the Perkiomen near above the reservoir this will work below a 9' will get you into the trout and warmwater species.
Other streams are also very small in width with very frustrating canopies stick to a smaller rod and then if you like an get to a brookie stream or headwater elsewhere in this stae you will be ready for bear with a 7'-7'6" 4/5.
Remember that with a 4/5 you have two line weight designations, supposedly one number is for a weight foward line the other number designation is for a double taper line, I use three lines per rod, if its a five for example i can use a four weight and speed up my casting stroke, or the five as listed, or if theres wind or bigger water i just put on a 6 weight.I have become convinced when you buy a reel that you shoul get two extra spools, amke sure the reel is for the maine stated line as in this case 5 weight and then you know that on the 4 weight spool you might need a whisker more backing, on the 6 weight spool you can take of a lil bit of backing, face it all this baloney about backing for insurance is bunk unless you are catching or fishing for big trout ..meaning measured in pounds and landed by being tailed . Only two maybe three places in Pa where i can say without a doubt you will see your becking with a decent fish.#1 the Delaware river..these fish are strong as heck even the lil guys, #2 the Lehigh same applies,#3 the Allegany{sp?} near Warren.Can't speak for the Yock.
Tight Wraps & Tight Lines
Rick Wallace