Sega planetariums are selling for $500+ which is too much for my budget. Also, a person in some review said Sega's are overpriced and not of high quality, and it would be better if he purchased projector and plugged into computer/google sky/stellarium..
That gave me an idea to proceed with projector, however when searching for wide angle lenses I come to another disappointment in terms of pricing.
http://navitar.com/product/hemistar-dome-lenses.aspx
plus good projector could go above $10k in total...
Finally, I decided to continue with cheaper option so I purchased Chinese NCO 907M projector on the eBay for $300, then experiment with some wide angle lenses.
The worst case scenario, and at the end of the day, I am sure projector will give us some fun
Cheers