I have a couple of heads that I like to use on my Bogen 3021 and 3001 sticks. At the moment, I have an older heavy duty Linhof ball head mounted on the 3021, but I also like my old Manfrotto Pro Ball model 168 (the one that uses the hex shaped QR plates). I use the RC0 QR adapter on the Linhof head. My third choice would be a 3047 3-way head, but to be honest, I tend to keep that one on my 3036 sticks these days.
I personally wouldn't use a 3001 with anything bigger than 6X6 with the legs completely extended, and that's even pushing the limit. Sure, it's rated for 11 pounds, but I doubt that it's really stable enough for 4X5 use - especially if you're outdoors with any amount of wind.
I've looked at a lot of carbon fiber sticks but couldn't get past the sticker shock when comparing price to performance. I've found that the best bang for my buck was getting a Berlebach wood tripod. It's light, does a great job of absorbing vibration, and the model I have (the 2042) holds my rather heavy 5X7 rig rock steady. I bought mine used (from a fellow APUG'er), but even at the new-in-box price, it's a great value.