You might look for country western lessons in your area. I live in a small town in N. NM and drive about an hour each way for ballroom lessons, but I started lessons locally with country western. The techniques for country western carry over well into ballroom, and I am constantly amazed at the number of 2step moves that are also used in american smooth. My instructor says that now you see country western dancers doing international standard syllabus moves too.
As for tapes, the Dancevision tapes are very good. My husband and I use them to supplement our lessons. I especially like the ones by Victor Veyrasset and Heather Smith, as they are very thorough.
It seems to me the biggest problem you face is not having a dance partner to practice with. As valuable as practicing your part alone is (in terms of knowing the footwork, etc), I don't see how you can really learn a move without dancing it with someone. On the other hand, points of technique (especially footwork) are often best practiced alone. And if you have a full length mirror it can be of real benefit for studying your latin technique. At least that is my experience.
Before I met my husband (we met through dancing), I practiced countless hours by myself. I found that getting the basic techniques down pat yielded the most benefit.
