I'm new to this forum, but.....
I would recommend Athearn, diesel, HO with Kato track. The sets are relatively inexpensive and Athearn builds bulletproof stuff. I hope your husband (and YOU TOO), enjoys this wonderful hobby. It can be a very rewarding endeavor and can be as simple as you like or as complicated as rocket science. The choice is yours (his).
I would recommend Athearn, diesel, HO with Kato track. The sets are relatively inexpensive and Athearn builds bulletproof stuff. I hope your husband (and YOU TOO), enjoys this wonderful hobby. It can be a very rewarding endeavor and can be as simple as you like or as complicated as rocket science. The choice is yours (his).