personally i would rather have top end alloy than cheap carbon. or if i could find the right builder a steel frame made from oversize and shaped deda eom* (or similar tubing) possibly a brian rourke but that would be over your budget.
shaped tubing that is nearly as wide as the bb shell, stays are trianglular shaped then into round. build a stiff frame that's not heavy.
personally i would rather have top end alloy than cheap carbon. or if i could find the right builder a steel frame made from oversize and shaped deda eom* (or similar tubing) possibly a brian rourke but that would be over your budget.