If you can afford the fuel to feed 160-180 HP and a 100 hourly, then go ahead, a great aircraft, great speed and performance that you won't be disappointed with! I wouldn't be expecting any massive cost blowouts unless the engine is tired as some builders use used or close to out of hours engines.
The 7 is slightly more roomy but I wouldn't discount the 6 as it is very similar.
Some are still registered under the old ABAA category so international ops are still allowed with most being experimental these days. Prices seem to range from $90k for a 6 to $150k for a good 7.
You will be up for LAME rates unless you build it yourself.