It is nothing to install a 220v plug. If you truly are going to use the welder, get a 220v machine. You can weld 1/4 inch with a 110v machine after you prep all the edges and do multiple passes. It will take you forever to get anything done and the duty cycle on a 110v machine will come into play.
110v machines are great for portability and body work, if you are doing structural work they just become a hassle.
It boils down to this... like me, you're not a professional welder with multiple welding credentials. It'd take a lot of experience and bad results to finally get to the point you could finally weld 1/4" steel with a 110v welder (but it'd take multiple passes). I had the biggest 110v (140 amp) welder you can buy and it was barely adequate FOR ME to weld on big pieces of 3/16"... they were big enough that they were absorbing too much heat for my 110v welder to keep up with which made my welds barely adequate.
For Joe-average who just wants to weld up to 1/4" without a lot of fuss, you REALLY want a 220v 180 amp (or better) welder. I sold my 110v 140 amp Hobart welder to get my 220v 180 amp Miller welder and just going to that new welder helped my welding quality a LOT. Since you say you want to weld 1/4", don't mess with a 110v welder... it'll just prove frustrating. My 110v welder proved frustrating even with big pieces of 3/16".
there is a lot of good info in this thread .... J.B. and Rustywrangler both make the best points here ...
Can it be done with a 110V welder ... definitely, if you have the understanding, experience, and proper tooling.
can it be done with a 110V welder in the hands of someone that has no experience. Definitely not.
i really suggest a MillerMatic 180 for most beginners ... simply becuase it has the power to burn in hot ... but its small and portable (no larger than the MM140) and its not going to take 10 years to pay off.