Unless you plan on continuing to weld on a consistent basis, I would just purchase a $25 plain jane helmet with a 5" x 4" lens, shade 12. If you plan on continuing to weld, I would invest in the auto darkening hood. Hornell makes a good unit (Speedglass), but can be a little pricey. At the local welding shops around here, you can get auto darkening hoods for under $100 any day. The only issue I have is that the auto dark operates at like 1/250 of a second. That sounds fast, but if you tack together and weld out say a trailer, you can have hundreds of welds. 250 welds (or weld starts) = 1 second of flash. It doesn't take too much welding and you are exposing your eyes to the "flash" for more than you think. And then you won't realize the effect it is having on your eyes until 5-10 years down the road. Just my $. 02
Chris Webster