Thinking about foster/adopt... again.

I've been thinking about it a lot lately.  My 3 yr old is a perfect angel   She was also foster/adopt, but was placed with us as a newborn. 

Prior to her, we had fostered a 2 year old with the hopes of adopting but she was reunified at 4 years old.  We are still very close and see her often

Hubby and I are at a point where I feel we are getting too old for newborns.  I would absolutely love a newborn, however I feel it would be a disservice to the child at some point due to our age and energy levels/health.  I know it's not a huge difference, but if I had to pick an ideal age, I think we'd be great with another child similar to the age or slightly older than our LO.  

I haven't spoken to hubby about his yet.  Our initial plan was to adopt one, and consider a second later.  I want to bring it up soon I think, but want to make sure I'm really ready.  I'm not sure I am.

Hubby has two teens from a previous relationship.  One is 20 and the other 16.  We have the younger on weekends.  Then of course we have our 3 yr old.  And our former fosterchild comes over quite often, most weekends.  So things can get hectic at times.  However during the week when it's only LO, it just seems so quiet and lonely for her (and us).  Sometimes it doesn't feel like a complete family.  My concerns are I fear the worst...being overwhelmed with a special needs child.  We had it so good with our two placements that I fear we are bound to be presented with something more difficult.  I don't want it to damper our family dynamics that we have now.

I guess I'm just venting.. I don't know for sure what I want.  I keep going back to wanting to fost/adopt one more though.  Should I just bring it up to hubby?  For all I know, he could be against it.