You are quit the younger sibling, that is fantastic. I will suggest a Millermatic 135. It will be slightly above the amount specified but it is a fantastic machine, and repairs are rarely needed.
An online source and link if it helps, http://www.brwelder.com/indextemplate.cfm?file=shop/detail.cfm&ID=13&SubCategory=1
Your a good heart, be well!
pjseaman
As stated, The Miller is a very good machine. You might want to check where your brother will be using the machine. Does he have 110 volts or 220? Does he have enough amperage to run the unit. Economically speaking, the 110 volt machines are a bargain. Get something you can get parts for, Hobart, Lincoln or Miller. Consumables, by this I mean, tips, cups, gas and liners need to be replaced periodically. I own a Lincold(220 volt with gas) and have built, a saw mill, tractor implements, house parts, garden art... the list goes on not to mention repairs for everyone in our town..
I think its great you are doing this for your brother. The satisfaction he'll get can not be measured. Good luck!