ok im loooking for a cat hull about 35-40 inches. my budget is under $150.00. i am bulding an eletric boat and i wana build a cat but cant find a hull.

You're not going to find a hull that size new for that kind of money.

the how much do i have to spend
i dont care if its used or not

the smallest ill go is 29inches

The Aeromarine .21/.45 Sprintcat retails for $159.95 (according to their web site) and is 29" long.

FunRCBoats also shows the Aeromarine Mean Machine hull in electric and nitro versions for around $175. This hull is also 29".

i saw that but i dnt think that will run in 6-9inch choppy water

Even a 35-40 inch boat I wouldn't run in 6-9 inch chop.
Seriously, what you're asking for the price and size is not going to happen. You never mentioned in your previous postings about running in water that rough.
In a boat the size that you want, you're looking at a big motor to push it plus a lot of cells to get any real speed.

The biggest cost in a hull is the labour. Consider finding a plan and building.

i think im gona buy the Aeromarine Avenger Mean Machine cat