24" Sand Filter Recommendation (..and a How To)

Hi all - I'm looking to replace my very very old sand filter - a Hayward, 24", 3.14 sqft with the plumbing side mounted.

I'd like for it to be so simple as to just remove the old filter and put in the new...with the plumbing fitting the current height/spacing. I'm not sure I'll be able to do that though...so my questions are:

1. Any recommendation for a cheap filter?
2. The Hayward top-mounted filter seems cheaper - is top-mount a bad idea?
3. Can anyone point me to a link with instructions of how to do the fitting/plumbing when changing a sand filter?

Thanks!
C