In reply to climbwhenready:
Sounds like you need a general purpose workhorse single rope, about 10mm diameter. All certified ropes are well made and very strong, so I wouldn't at this stage bother about features such as small diameter, dry treatment, unicore, etc, all of which push the price up. How long the rope lasts is much more to do with how you treat it than what the specs are.
Regarding length, if you're already anticipating trips to Portland, then a 60m is probably your best bet - there's a fair few 25m plus routes. Also, as you're not yet considering double ropes, a 60m single will give you considerably more flexibility at crags which require abseil descent (lots of those in the Wye Valley, for example). The downside is that you have to lug the extra 10m around, although you won't really notice that too much indoors, if you use one end, with the rest stashed in a (IKEA) bag.
For deals online, try joe-brown, banana fingers, urban rock, cotswold outdoor. For your needs the DMM Statement is fine, also Tendon Smart, Mammut Vertex, Beal Edlinger 2, and many more. If it were me I'd just go for the best deal.
One last tip - check carefully along the whole length of your new rope for manufacturing defects before you use it (rather than notice it as it runs through your hands while belaying). They're not common but they do occur, and dealers are understandably reluctant to exchange climbing gear after use.
Hope this helps - happy climbing!