Im so sorry about the passing of your beloved boy!
I got my 2 boys only about 1.5 months after my Stuart passed away. I was grieving very much for him, but my boys sat on my lap and licked my tears and my face, smoothered me with kisses and made me feel so much better! I couldn't imagine a house with no critters! I didnt feel guilty for getting my boys so soon afterwards. I did a little comparing with my beloved stuart, but I dont anymore. I think you should do whatever you are most comfortable doing!