Welcome Hazza,
I'd recommend you look at @Jabba_the_gut's build. I saw it at a Bass Bash last year and it's a beaut!
Old Front Door and a Shelf...
Your budget should allow you get a decent starter kit though. I echo the suggestion that you modify a kit body rather than make one from ply. I spent about £350 building my Ibanez tribute bass. The link is in my signature. I liked it so much I had to buy the real thing after so beware.
Well done for jumping right in though. Respect.