Henri and
to the site.
Your certainly right that aperture rules, and for that matter alone I would not suggest a refractor. While a good 80 - 100 mm refractor can be an excellent scope, you just won't see as much as through a 200mm SCT/Mak or newtonian. So from that point of view, the refractor is out(for the time being
).
A few more details might help to point you in a definate direction.
1. budget
2. do you want a mount that will automatically track objects or would you be happy to track objects by hand
3. Do you want goto. ie tell the telescope what you want to see and let it find it for you.
4. What sort of transport do you have
5. How heavy an object do you think you could carry for short distances.
6. Do you have to go up or down stars
At the moment I'm thinking 8" or 10" Dobsonian ($500 - $700) for manual tracking with great light catching power for deepsky stuff and with a good barlow lens for planetary and moon viewing.
If your buy an SCT/Mak then you will need an equatorial mount, preferably with tracking. A 5" Mak (good for planets and moon but a bit limited for Deep sky) on an EQ3 mount (smallest I would recommend and even then a bit underdone IMO) with dual axis tracking will start from around $1250 and an 8" SCt (better for Deep Sky stuff while still good for planets and moon) will set you back from around $1500 with dual tracking mount.
If you are thinking about goto, add another $1500 - $200 for an improved mount and goto harware and software.
Just things to get you thinking.
Cheers