We have both in our lab at school. I have 2 45's in my own darkroom and tend to like them better. However, that is probably because i have been using them for 30 years.
I agree with Paul, both will do the job, both are well made. With the Beseler you do change the condensor head for specific negative sizes.
Prices here are cheaper, however, which timer may be effecting the cost, type of easel etc. the last 45 i saw in a store that sells used equipment was about 300, however, the lens was a 50 not the 150, had negative carrier for 35mm and various other items that went along with the package. Looked in good shape.
The Omega, may be a better buy as it comes with a variety of negative carriers which may appeal to you, as the negative carriers for the beseler will vary in price used and about 90 dollars new.
Which one will need additional equipment to set and use with your present formats? That may help decide how much more you will need to spend or not spend.