For larger, firmer produce like pineapple, apple, cucumbers, etc., a centrifugal unit is perfectly fine and tends to be a bit easier to clean. Masticating juicers will handle just about anything including, berries, spinach, kale, etc.
For orgeat, we need a blender or food processor. A 4-cup Cuisinart FP can be had for $50. A Ninja blender can be had for $90.
A brand new centrifugal juicer, suitable for home use, can be had for as little as $65. A two-speed unit is most versatile. Ultrean and Hamilton Beach both make affordable models. Breville makes excellent units but start at $180. We use Brevilles in our programs.
Masticating juicers can be had for <$100, like this Omega H3000D. Ninja and Cuisinart both make decent, affordable models. Our juice bar uses a higher end Omega and it only struggles a bit with wheatgrass.
You can probably find a used centrifugal on EBAY for $50-ish and a masticator for $80-ish. I suppose it all depends on how important a new, warrantied model is to you and whether new is worth an extra $20 or so.
Fast, easy - http://www.amazon.ca/Breville-Juice-Fountain-Compact-BJE200XL/dp/B000MDHH06 $110
I have a $400 masticating and I would prefer to use the breville one shown above. It's got a huge feed slot so you can stick 1/2 or a small whole apple in at once. You can pound a bunch of celery/carrots through it easily.
This is a centrifugal one step up: http://www.amazon.ca/Breville-JE98XL-Two-Speed-Juice-Fountain/dp/B003R28HWQ/ref=pd_cp_k_0
A decent masticating juicer, which is slower and requires more food prep would be more than $200, http://www.amazon.com/Omega-J8006-Nutrition-Center-Juicer/dp/B001L7OIVI $289 plus shipping.
I just bought this baby off Amazon for a pretty good price. (Just under about $150). It seems like a good mid range juicer, not too expensive, but still seems good quality and easy to clean. I'm a guy about your size as well... with a similar goal. As soon as this juicer arrives, I'm gonna start with a 10 day juice fast... and I still feel good, consider going for 30 days. Looking forward to kickstarting my health again. Good luck to you!