Miller2009 said:
The tank size is 84x44x58cm (22x17x23 aprox) I've already got
2 guppies
1 blue ram
1 common plec (beginners mistake)
5 neons
3 julii cory (defo upping to 6)
2 pearl gourami
So it's the following I would like
1 angelfish
5/6 Boesemani Rainbows (which may be too many plus unsure if LFS stock them)
1 aquatic frog (only one they stock)
I'm very much thinking of rehoming the plec and replacing him with shrimp
For the sake of the fish, you need to decide on either rehoming or getting a 6-foot tank for your "common plec" and IMO this needs to be done before the fish hits 10cm (which at best is ~33% of its 30cm adult size, depending upon species it could be a lot closer to 16% of its 60cm adult size).
Excluding the unsuitable plec, you currently have ~90cm of adult fish, on the basis you are upping the Corydoras julii group to 6. However, even then, there are compatability issues...
German Blue Rams are "high end tropical" cichlids that need at least ~27C, which will not be good for several of your fish (the Pearl Gourami are the only species that is fine, others would need to be replaced with the likes of Cardinal tetra; Corydoras sterbai). Bolivian Rams are far more "mainstream tropical" and do fine at ~24C, which is fine for your other fish.
Are the catfish really the rare julii and not the commonly missold trilineatus? The latter are "temperate" corydoras (~16-24C in a heaterless tank that changes temp with the seasons), just like Peppered, the former are "mainstream tropical" but you are unlikely (not impossible) to have them.
Neon Tetras will not do well is high end tropical temps, they are typically swapped for Cardinals above ~25C.
Your "wishlist" are not good choices for your current tank...
Angelfish will eat your smaller fish and the tank is a bit cramped even though I presume it is 58cm tall.
Bosemani Rainbowfish need far more room, at least 120x30x30cm, but ideally bigger.
Frogs are not good at competing for food, always a risk mixing them in "busy" tanks.
90cm of fish in a 165l (your tank dimensions need rechecking to levels the water is filled, 84x44x58cm suggests 214l) is towards the upper limit. If your tank was suitably stocked (which it is not IMO) I would say just gradually boost social fish numbers to 8 max and then called the tank heavily stocked.