WOULD LIKE TO BUY A WET GRINDER / NEED HELP

[ABCD]

Thanks in advance for your help.
I would like to buy a 110 volt vertical wet grinder of at least 1.5 L size for use in the US to make dosa / idly / vada etc. batter.

Santha 1.5 L and Premier Wonder grinder 1.5 L are vertical models. They look compact and I like their design.

http://www.santhagrinders.com/maestr...html#technical
http://www.hotdishes.com/premierwondergrinder.htm

Santha 1.5 L grinder runs at 990 RPM and costs about $250.
Premier Wonder 1.5 L grinder runs at 1440 RPM and costs about $155.

1) Any comments on performance, quality and durability of the above two models?
2) Would appreciate input about Pros and Cons of buying one of the above mentioned models compared to Ultra and other well known wet grinders.
3) Are there any advantages in buying a horizontal wet grinder instead of a vertical wet grinder?
4) Are there any other good wet grinders which come in vertical models with a size of at least 1.5 L?
5) Is it desirable to buy a wet grinder model with a higher RPM?
6) From the price and RPM, Premier Wonder wet grinder seems like a better buy compared to Santha. Any comments?