Gift certificates....good idea. I know TractorHelp.com has a wish list you can build and send to someone. Someplace like Surpluscenter.com, I usually e-mail part numbers, descriptions, and quantities to her.
I've found ask for some huge stuff, then you're pretty likely to get the medium sized stuff. Just ask for medium sized purchases, and you'll get the small ones. Asked for a chrome grill guard for $900 for mine.....ended up with the $250 worth of hydraulic lines and fittings I asked for.
It's all about knowing how to work the system boys....LOL