I had a mpt valve leftover from another project. I don't think they are available at Lowe's or Home Depot, but they do have fpt valves and pipe nipples. Just make sure the valve is suitable for hot water. Using a nipple will also allow you to change the valve location, which may make accessing the handle even easier.
I purchased my valves from McMaster-Carr in Atlanta.
"One of the best lessons I've learned is that you don't worry about criticism from people you wouldn't seek advice from."
William C. Swinney