In your position I would not touch any previous UMAT company now claiming to prepare students for UCAT with a 10 ft pole.
They will claim that they 'anticipated' this change and that they have already made resources. Do not fall for this.
The UCAT change was very unexpected for all stakeholders. Yet Icanmed is claiming that they knew this was coming while Medentry claims they have been preparing students for the UCAT for 20 years LOL.
Anyway, to answer your question, I would first direct you to the free resources UCAT makes available for all students for free!
http://www.ucatofficial.com/ucat-anz/preparation/Secondly, you need to know that the UCAT is the exact same as the UKCAT that has been running in the U.K for many years now. This means that all resources available there are applicable to the UCAT. In your position I would be searching amazon, ebay and other book websites for UKCAT training materials. These are often very cheap $30.
If you do feel you must have some sort of preparation course I would advise you to look for a UKCAT one. Although from my searching I have found that there aren't that many as so many cheap resources are accessible in the form of books.
Do not fall for UMAT companies claiming to suddenly be experienced in the UCAT!