Well, for target work in IPSC I would go with a fibre Optic front sight. Ameriglo has the best Tritium sights IMHO. I would say trijicon is good as well, but they are basically Ameriglo. Mepro are ok, but I have both. Ameriglo has a brighter white ring around the tritium insert. The inserts are about the same.
I used to use a Mepro rear adjustable sight, and Ameriglo Tactical front sight. I used that at the 06 nationals. i have since switched to PSI fibre optic adjustables. The choice is yours. I use a PSI set on my stainless USP, and will soon have the adjustable Mepro/Ameriglo sights on my secondary USP.