i was browsing ebay and saw some retro fit metal halide kits for some alright prices and was wondering wat you all might think of them

175watt retro
http://cgi.ebay.com/175W-Metal-Halid...QQcmdZViewItem

250watt retro
http://cgi.ebay.com/250W-Metal-Halid...QQcmdZViewItem

i dont know wat they usually go for but i thought that was a reasonable price and having metal halide lighting. ohter than that would 250watts be too much for my 20L? i have a crocea clam and its doing fine under 196watts of pc lights but i love how MH lights look was thinking of t5's but the shimmer looks too good!