I'm not sure such a site exists because there's no funding to independently test multiple brands of probiotics. Your best bet may be to pick a few brands you're interested in and contact the manufacturer. Ask them to supply information from independent testing labs on quality, viability, etc.
Diagnosed with ulcerative colitis spring 1999.
Maintenance dose sulfasalazine.
Probiotics, l-glutamine and fish oil caps. George's aloe vera juice. Oregano oil antibiotic, antiviral, antifungal. Long-term remission with only minor blips.