I think Todd's talking about integrating to one of the Infor ERP packages. Infor has a strong and getting stronger integration between most of its ERP's and Infor CRM (fka Saleslogix). The integration protocol is very similar to SData, which Sage CRM did a pretty full implementation, so it's possible.
That said, if your prospect is now using Infor ERP but doesn't have Sage CRM yet, they'd be crazy to arbitrarily decide to not use Infor CRM. Infor CRM is all web based, has strong functionality in most areas. They should do a 3-yr TCO on Infor CRM first. If it doesn't do the job, then look to something else.
Frankly, if they are a good fit for Infor ERP - larger than most Sage 100 customers - then Infor CRM is a decent fit.
If this is an older Infor ERP customer, on the smaller end, they should take a hard look at whether Infor is an appropriate fit for their ERP! That company is becoming very expensive for customers on its smaller end. The functionality it's been adding is all aimed at more sophisticated customers, IMO.