You sure you need to rebuild it? If it's just the head gasket, swap those and wait on the rebuild. Better to do it right the first time. For about $500 more you can get a 306 pro bullet from DSS or another engine shop. Look around and you can find good deals.
If you have to do it now, I'd go with forged pistons and stay with the stock cam. And don't worry, the rest of that $1k you have now will be eaten up with miscellaneous expenses you haven't thought of yet, like lifters, pushrods, gaskets, bolts, thread sealer, locktite and various parts and tools you don't know you need yet.
All that little crap adds up fast.