There are quite a few 4 ohm 410 cabs available, but most are of the ported variety. The 410HE is a sealed cab similar to half of the 810, but is a big no go being 8 ohms. The 410 HLF is a 4 ohm cab, but a lot of Guy's dont really like it because of it's tone ("dark or bassy"). I have heard some Guy's around here say, that the 610HLF is a kind of middle ground between the 810E and 410HLF tonally. Before building My DIY cab, I was using the discontinued SVT 412 HE. Which was a excellent sounding beast of a sealed cab. The main reason I sold it in favor of My DIY cab, was the weight factor (100 lbs) and having to dead lift it into the back seat area of My truck all by My lonesome. IMO- there are a lot of great sounding cabs that pair well with SVT's, just dont limit Yourself to speaker size topography. There are some really nice 410's out there, but there are just as many or more cabs that will work and sound great that aren't 410's. Let Your ears, back, and wallet help You make the decision. FWIW- If an Ampeg SVT 810 is what You want, dont let the new prices discourage You. In the past, I have found some excellent deals on used ones on Craiglist(less than $500.00).