Hello Everyone

Im having some trouble whats the best laptop for this scenario, Something can replace the huge desktop i have as it takes up more room than my whole family, so it will have to be powerful, Secondly it will want to take it into collage to write up stuff, and be able to design electronic circuits and simulate them (any suggestions for the software for that), so will have to be portable and have a good battery life. My thoughts are on this http://www.tiny.com/packages.php?prodid=10580 which looks like a kickass powerful laptop with its Athlon 64, Radeon 9600 and DVD rewriter. The question i ask u is how much battery life could i expect (if i remove the DVD drive and all unnecessary subsystems) are there any better speced alternatives for the price of £939, would it be worth waiting for a Athlon 64 2800+ alternative (more battery life) and how much would a extra battery cost.
Thanks for any help