Yes, Thai concentrated paste is fine. Be aware of something. Thai Tamarind, be it in seedless blocks or paste, comes in 2 distinct forms. One is called SWEET TAMARIND, and is distinctly not sour, and the other is SOUR TAMARIND.
Tamarind, the ripe fruit, in any case has over 40% sugars. It is the degree of acid content that determines "sweet" versus "sour" types. Tomatoes & peaches have a similar situation, where the low-acid types seem considerably sweeter.
Don't worry too much. Here is an example of what you seek in an Asian market, with pictures: http://importfood.com/sads1701.html Pure Tamarind Paste, Seedless, 17.5 oz ja
An Indian mail-order in your neck of the woods that I found on Google: Patel Brothers
1251 W. Fowler Ave, Unit F
Tampa, Florida 33612
post edited by pimple2 - 2011/07/17 14:16:55