Who did you train with? There are lots of choices but your training should have given you a decent foundation in product chemistry, application, etc. to make a fairly well informed choice. As Techs we are always spending money on products because we're looking at the newest innovations, checking brands against others for the best result for us, so don't expect to find one and never buy anything else again 'cos it ain't gonna happen!! LOL.
You may want to narrow the choices and get trial packs from the top 2 or 3 and see how you go. If you have a brand in mind, use the search option on here to check for any info about it. If there is nothing on here then I'd avoid it, we have over 5000 members over the years, if something hasn't been mentioned on here it's probably not well known (aimed at the DIY) a pro brand, or any good. Avoid those brands that are available on FB, Amazon, eBay, etc. Yes reputable brands have Social Media pages but it won't be their only way of selling.