Can someone help me decide between an amp and an integrated amp?

I’m looking to upgrade to Maggies, so I know I need more power than my Creek 4240 SE has. I’ve been recommended a Classe CAP-151 integrated for $800 and a PS Audio Stellar 300 which lists for $1500, but they are giving a trade in of full original value for your old amp (800), which is an awesome deal. I have an IFI Pro headphone amp for a preamp.
Is there an inherent value in having separates versus integrated? Is there a problem using the headphone amp as a preamp? Has anyone done that trade in deal, offered out of Boulder? The Creek sells for less online.
Thanks for your help!
Hi not sure which Maggie's you intend to purchase and have no experience with the amps you mentioned but I did use a Parasound integrated with 1.7i and the sound was amazing.
I guess separates or integiverated just depends on the best available deal. Just be sure you have enough current to drive Maggies.
Maggies, huh? Put Bryston on that list, be surprised how many maggie owners prefer Bryston. Should be able to find something used close to your budget, but a few more $$$.
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Well my man, you have opened a can of worms. Here is my two cents, in general, separates sound better given similar build quality. Different power supplies running pre and amp make a difference. I prefer dual mono amps to a single amp for better separation and imaging. As was mentioned, you have flexibility with separates to mix and match for desired sound. Down side is at least one more power cord and one more set of interconnects with separates. While you don't have to spend a fortune on ICs and PCs, substantial gains can be made by upgrading over stock. Rack space is also a consideration. There are some very nice integrated amps out there but I am partial to separates. For what it is worth, I think what Classe CA series, McCormack DNA series, Bryston SST and Belles (what I still own) are tremendous amp bargains in the used equipment arena. All these are pretty much bullet proof. I also love tube power amps, especially well executed EL34s but I am tired of hassling with power tubes and the cost of nice NOS tubes is getting redunkulous as well as needing more power for my 4ohm 86dbB speakers. All of life is a compromise, so now I am happily running my Belles 350A Reference amp with a Mapletree 6NS7 tube preamp. With your Maggies, SS is the way to go, unless you rob Fort Knox and buy some bemouth tube monos. I would personally start with an amp with 200wpc into 8 ohms which doubles into 4 ohms. If you want a Luxman integrated, go the 507 route and not the 505 because the 507 will double into 4 ohms (even though I think you need more power than these for the Maggies) plus it is just a better piece of equipment.  I ramble and thus digress, I like a good SS power amp for control and authority (and worry free operation) and a nice tube pre amp for warmth and dimensionality. You could probably do very well with a couple of well selected previously owned pieces in the $2-3K range for both a quality SS power amp and a tubed pre. My 2 cents, YMMV.