NZFF

Can anyone direct me to any good freeware or payware Aircraft..............
I'm looking for:
Boeing's (preferable with FMC's)
737-800
747-400
777
787
Airbus (preferable with FMC's)
320
321
Quality renditions are preferred....
Many thanks

For the Boeing's PMDG , but I think Steve aka: Cowpatz would give you a cheaper solution with another product, and as for the Airbus 320/21 series , Aerosoft Airbus Extended would possibly be the only one out there and a high but reasonable price.

I really like the iFly 737 and it is my go to regional jet. It has great features and unlike the PMDG aircraft is capable of flying the RF leg types required for the increasing number of RNP approaches available. The RF leg type allows for curved approaches. It also includes weather radr integration with Active sky next etc.
With iFly you also get the whole range from 600 to 900 except cargo variants as well as BBJs. It also has 2D panels (as well as VC) if you prefer them. The PMDG is a great machine as well but only has a VC. The graphics are superior in the PMDG aircraft but I find the iFly ones fine.
The iFly 747 is great as well and great value for money. It has some great features including the ability to uplink enroute and descent winds from your weather program into the FMC (a great time saver, especially in the real world).
I have not flown the PMDG 747 as with having the iFly version I don't have the need.
You would need to check but I am sure that with iFly (vai Flight1) there is a 30 day return if not satisfied.
Just beware about making any major purchases that if you intend to upgrade to P3DV4 (which is mooted to be coming soon) then some of your purchased add ons may not work in 64 bit or there may be a good delay whilst developers update them to work in V4. There may also be an extra cost for this as well.
As for the A320 then the choice is between the Aerosoft A320 and Flight Sim Labs A320. The latter is a study level sim that reproduces the aircraft very accurately (including FBW) but by all accounts is also a little heavy on frames. It still doesn't have the secondary flight plan option but this is will come shortly in an upcoming service pack.
As for the 777 then the PMDG 777. Some have the Captain sim 777 which is a sort of open beta payware. Not fully finished.
There is no decent 787 yet. Quality wings are working on it but no idea on release.