If you go with the IRMT (and possibly the proton therapy also), there will likely be at least a 2-3 week period where having help with shopping, food prep and driving to appointments would be a really good idea. You might MD Anderson about this - a reputable company that specializes in elder care would have caregivers that could accomodate these needs.
Also make sure you have sister and finance stay in contact with you via skype (or equivalent). It is critically important to maintain nutrition and especially avoid dehydration, and having your dear ones keeping an eye on you.
Even if you get the IMRT you will be at a top flight institution for your treatment. It's wonderful to have family available, but I think with a little creativity it can be managed. The American Cancer Society in Houston may have volunteers that could help.
Best wishes and congrats on the success the induction chemotherapy thus far!
Maria