I hope all is well. I'm guessing that you're looking for more budget type of transformers which I certainly can respect, oftentimes cheap is cheerful! There are two budget options for new transformers out there that come readily to mind.
One would be Edcor. I really like their transformers - both output and power. They make a 3K to 8 ohm 10 watt one here: EDCOR - XSE10-8-3K or you can spend a bit more and get one with end bells that is actually 2.5K to 8 ohms here: EDCOR - GXSE10-8-2.5K
Another really budget possibility would be the Speco T7010 transformers. They have multiple taps and just from memory, I thought they had one tap that would provide close to a 2.5K primary. They can be had for around $5.00 if you look around online. For fun I ran them up to 50ma at around 320volts before on a EL34 amp and they were beginning to show signs of saturation, but were fine below that. They start to have rolloff at around 100hz but aren't terribly thin sounding and have a respectable midrange sound...overall quite pleasant and much better than expected for pocket change ;>)
There's a guy on ebay with username Gobble75 in Phoenixville Pa (not sure how far that is from you), that used to have the T7010 transformers (probably still does but doesn't have them listed right now as far as I could tell). I've bought a variety of things from him over the years and he's a cool guy. He might be worth contacting as well to see if he has anything that would work (he always has a ton of surplus tube gear!)
Good luck finishing your amp project. Little single ended amps are a lot of fun!
There's a guy on ebay with username Gobble75 in Phoenixville Pa (not sure how far that is from you), that used to have the T7010 transformers
A couple of years ago I started an amp using the 25C5's and this transformer. I never finished it before I got bored with it though.
10W Speaker Line Matching Transformer | TR7025-10W (TR702510W) | Distributed By MCM
Here is a thread you may find interesting:
Parsimon: An Ultra-Cheap DIY Class AB PP Pentode Power Amp - AudioKarma.org Home Audio Stereo Discussion Forums