I don't see a problem they are both sources and not really a competeing sponsor.
For what it is worth Spider has had a Sponsor house profile from when they first started but this will be the final season.
As they grew in size it has come to the point of being a cattle drive where most sponsors offer very little to the rider instead they are just looking to create customers that must purchase their product at slightly reduced pricing. We are going back to the indivual approach of obtaining sponsors and sticking with the ones that have supported him in the past.
No problem in doing both...just pay attention to individual contracts to what other companies they say you cant buy stuff from. I used sponsorhouse last year, and got a bunch of sponsors. It's not all that it cracks up to be. I didn't do it this year until I found out you could do 5 free applications. I did 5 apps to ones that had good deals and supported me last year. I got 4 offers. I'm happy.