The answer is always "depends"... haha
I'd go with three 15.5gal stainless sanke kegs and converting them for a HLT, mashtun, and kettle if cost/time/effort/space aren't concerns.. This will be a bit of work (if you can even find 3 of those kegs) but this setup would take a while to outgrow and you ever decide to go electric, the same equipment can be re-used.
If your goal is to make 10gal batches the easiest/cheapest way possible (like most of use on here), you would need at least a 15gal brew pot and a 10gal mashtun cooler (15 gal would be ideal) and a 10 gal HLT pot like you said.
If you ever have any questions or need to borrow anything let us know.. I'd be more than happy to have you over for a brew day or lend some equipment while you get setup for all grain (it can get expensive quite fast, the list of wants and needs never seems to end with this hobby).
Oh, by the way, another thing I would change from the start would be kegging... Washing/sanitizing bottles sucks especially for 10gal!
