Thaught id wait for you to jump in 1st bribie!
I ususaly shoot for around 20% of the malt bill if im doing a Rice Lager. The beer ive just put down for the VIC caseswap (which is fantastic BTW) has 20% rice. This was cooked in the rice cooker with WAYYY too much water to turn it to congee, dumped into the fermenter with my strike water and then doughed in ontop.
I did a high temp protein rest (55deg) and a 65deg sacch rest. The palate is very much like a commercial/streetside Bia Hoi which is what i was trying to achieve. The only downside i had was the super-mega-awesome efficiency i ended up with which bumped it up to a 5%abv beer with my final gravity. Thankfully the hop/malt is still balanced well as i evened it out with some extra magnum and perle just before flameout.
If you wanted to do this as an extract (which i'd recommend over a kit) i'd sub out the pilsner malt with pale extract and still do a steep of some carapils to get the hint of pils/grainy sweetness. As for the rice, well you would need to use the rice syrup bribie mentions or you can get some from brew shops that is a clear form. Ignore the water additions if you are not at that stage of your brewing. You can get away without it when brewing with extract.
Oh also when using the rice syrup, i dont know if you will end up with the same result as when you mash with rice. The enzymes in the malted barley turn the starch in the rice into maltose. You also get a specific aroma when using rice in beer, its not big, but its noticable. I dont know what the type of sugar is in the bottles of rice syrup from a LHBS but i'd be doubting its maltose.
Have attached a pic also
Reunification Express - Viet Street Lager
Standard American(viet) Lager
Type: All Grain
Date: 13/09/2009
Batch Size: 25.00 L
Brewer: Braden
Boil Size: 33.38 L
Boil Time: 60 min Equipment: My Brew Pot (40L) and Frosty Cooler (38L)
Brewhouse Efficiency: 68.0
Ingredients
Amount Item Type % or IBU
3.50 kg Pilsner, Malt Craft Export (Joe White) (1.7 SRM) Grain 70.0 %
1.00 kg Rice, Flaked (1.0 SRM) Grain 20.0 %
0.50 kg Carafoam (Weyermann) (2.0 SRM) Grain 10.0 %
10.00 gm Magnum [12.50%] (60 min) (First Wort Hop) Hops 15.0 IBU
10.00 gm Pearle [6.00%] (20 min) Hops 4.0 IBU
1.00 gm Gypsum (Calcium Sulfate) (Mash 60.0 min) Misc
5.00 gm Calcium Chloride (Mash 60.0 min) Misc
1 Pkgs Bohemian Lager (Wyeast Labs #2124) [Starter 2000 ml] Yeast-Lager
Beer Profile
Est Original Gravity: 1.041 SG
Est Final Gravity: 1.012 SG
Estimated Alcohol by Vol: 3.8 %
Bitterness: 19.0 IBU
Est Color: 2.9 SRM
Mash Profile
Name Description Step Temp Step Time
Protein Rest Add 7.50 L of water at 63.3 C 55.0 C 20 min
Saccharification Add 6.50 L of water at 79.5 C 65.0 C 60 min
Mash Out Add 10.00 L of water at 96.1 C 77.0 C 10 min
Notes
Mash: CaS04 1g, CaCl 2g
Boil: CaSO4 1g, CaCl 3g