Hi Russ,
Don't even think about building up a 260. it is a very weak engine. If you want to keep your 260, you could pick up some easy horse power by getting a 289 crank, short rods and a set of stock pistons. You will get about 272 cid. But buy the time that you build this up, you could pick up a 302 short block for less $$.
Your best choice would be to use a 302 short block with a roller cam and 351w heads. You can use a 6 bolt scatter shield bell housing for safety and a set of headers. I think that Tom Hall at STOA has clutch slave cylinder mounting brackets for 6 bolt engines for sale. You would have a lot of power with the stock 302 cam, but I recommend a mild roller cam from Ford or crane cams. You will also need a set of traction masters to keep the rear tires on the ground.
Although I'm using a Boss 302 block and steel crank, Ford lamans rods with TRW pistons with GT40 351W heads in my Tiger, I'm thinking about putting in the 331CID stroker kit and Ford SVO aluminum heads on just for fun. But then, I have so much power now, don't really need it. But then..... Mo power is nice, but its hard on the rear tires!
Good luck with your project.
Al