It would certainly do the job, but you dont need it.
If you are mash brewing - then all you need to do is a normal cereal mash for yor rice, or use a flaked/puffed rice product. Unless you are planning on using 50% rice or something (which would be silly) you wont need more enzymes than you'll get in the base malt you are using. Thats the rice taken care of.
Then for dryness - you should be able to get what you are looking for with a long, low temperature mash. If you really dont feel that you will be able to get your beer dry enough with just a mash regime, then you can buy "dry" enzyme from most homebrew shops. Its just an amyloglucosidase and it will dry your beer out as much as you desire and probably more.
The product you link to is a more complex one that as I said, would certainly work - but no need to to go exploring the quite large world of brewing enzymes for the job you want to do. The stuff from your local HB store is more than adequate. Besides, if its like half the other enzyme preparations out there, you'll be lucky to be able to buy it in anything smaller than a 5L container.
Most good Pils malts will convert a pretty high percentage of adjunct just fine, the diastatic power is high. 50% rice would not be pushing the envelope. Cereal mash or using precooked rice (absorption method, quick boil or microwave, whichever you fancy) thrown into the mash with enough water and malt to reach conversion temps will get you there.