You can go with adjustable sights, fixed sights, night sights or any combination there of. If you use the gun for concealed carry I would go with something like Novak sights. If you are more prone to shooting at paper and such I would go with a set of adjustable sights from BoMar.
If you can find the correct front and rear sight heights with a fixed sight set up you will be able to regulate the sights well and wouldnt have to worry about adjustable sights as long as you do not shoot a variety of different loadings and bullet weights.
The thing you will have to figure out between a conversation with Springfield and a conversation with the after market sight maker is if their rear sight will fit in the factory machined dove tail. Generally the fixed sight guns rear dove tail is smaller than the dove tail required for adjustable or after market sights. If this is the case you will need to have your receiver milled to accept the after market sight.
Springfield might even offer a sight that fits your gun perfectly.
Novak is offering a sight that will probably require some machining on your slide but its a low profile sight that is adjustable. I havent used or seen these sights in anything other than pictures but I believe they would suit your needs pretty well.
Here is the link:
http://www.novaksights.com/extreme_duty_adjustable_sight1.htmTake Care,
Scott