Advice wanted on which GPS to get

I'm looking at buying myself a gps system and am looking for some advice as to which ones work well as well as the pros and cons of certain systems. I pretty much just do simple grass work so tedding and raking etc but will hopefully get into doing more jobs like mowing, spraying and drilling in the near future and am looking for a system I can use that will allow me to ensure I'm doing an efficient job while not missing too much.

Budget wise, I'm looking fairly low down so I'm currently...

Advice wanted on which GPS to get