You can use just about any receiver or amplifier you want with those speakers. Just make sure that whatever you select has the features you want. I don't think Sansui makes anything for the U.S. market anymore, but both Yamaha and Onkyo do. You can see their current offerings at their respective web sites, and once you find a model you like, you can then search for a place to buy it. Just make sure you buy from an authorized dealer, if you want the manufacturer to honor the warranty.
If you are on a tight budget, you can go for something used, and then your local Craiglist might be your best option. But, of course, you need to always be careful when buying used; make sure it works properly before you pay for it and take it home.
