If you can get to a firewire demo centre I recommend you check their range - I've recently bought a dominator after surfing PU boards (shortboards and mals) for 20 years and the dominator is by far the nicest board I've had (it's light, fast, stronger). The reason I suggest getting to a demo centre is that you can try the boards for free and see what sort of length you feel comfortable on (rather than spending a wedge each time - most rental shops seem overflow with BICs and fairly shoddy old clunker shortboards that they couldn't sell). I'd also suggest that you get a hybrid fish shape rather than a fish - these are boards that are a blend of a shortboard shape and fish-like volume (the dominator is one example, others include the CI biscuit, JS Nitro, Simon Anderson mollusc).
Sounds like you are competent at paddling and catching waves - if so, don't be scared by getting a shorter board (assuming you surf regularly enough to get used to it and progress on it), Shorter boards are easier to manage (duckdiving, getting out when the shorebreak gets a bit hairy) and the difference in paddling speed is negligible (other than compared to a mal) given that for the most part you only need a good 5-10 second burst to get into a wave. I reckon the worst thing you can do is get a board that is both too long and has too much volume - it may paddle slightly faster and be a little more stable but will make your life difficult if conditions aren't optimum (if you can't duck dive it easily the difference in paddling speed will be offset by the time you'll spend going backwards in the washing machine).
If you want a book to read on the way - Nick Carroll's "Complete Guide to Surfing Your Best" is good (costs about £18 if you hunt around) and the 110% surfing videos are ok (though the first volume is mainly comprised of very basic information and both volumes are plagued by terrible music that can't be switched off - I reckon skip the first and get the second volume).
Good luck, and enjoy getting a shorter board - much more fun than a "fun" shape/length.