Ask advice for autoguider for EdgeHD 8" and AVX

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Hi all,

I think it's time to get autoguider for long exposure AP With below setup, I could get two minutes exposed picture without star trailing (FYI, I started my stargazing life last December, lol)

- EdgeHD 8" on Advanced VX mount

- .7x Reducer

- Sony a6000

At first, I considered Orion Awesome AutoGuider Refractor Telescope Package, but I've read some articles mentioning that it's weight going to be problem for my configuration. Next, I checked Orion Deluxe Mini 50mm package. However, it looked like working only with focal reducer and reaching to limit (imager/guider ratio 1:9) even with focal reducer. So I did some more research and make below list.

Product  / Price / Focal Length (mm) / Weight (lbs) / Resolution Power / Ratio W/O reducer / Ratio With Reducer

Orion Deluxe Mini 50mm / $185 / 162  / 1.2  / 4.77 / 11.99 / 8.39 

Stellarvue 60mm M60M3  / $199  / 225  / 1.375 / 3.43 / 8.64 / 6.05

ZWO 60mm with Ring  / $118 / 280  / 1.4 / 2.76 / 6.94 / 4.85

APM 60mm finder with Ring / £125.00 / 228 / 2.08  / 3.39 / 8.53 / 5.97

APM 80mm finder with Ring / £175.00 / 370 / 2.08 / 2.09 / 5.25 / 3.68

Orion ShortTube 80 / $119 / 400 / 3 / 1.93 / 4.86 / 3.40

Stellarvue F080M3 80mm / $249 / 300 / 2.2 / 2.58 / 6.48 / 4.54

Resolution power was calculated based on spec of ASI120MC having 3.75um pixel size: (206 x pixel size) / finder's focal length. 

Imager's resolutions were calculated based on spec of Sony a6000 and EdgeHD 8": (206 x 3.92) / 2032 and (206 x 3.92) / (2032 x 0.7)

Did I do correct math? If it is correct, ZWO 60mm finder looks best choice. However, I couldn't find real world examples using ZWO 60mm finder as autoguider scope for EdgeHD 8" and AVX mount. May I get any advice or suggestion?

Thanks!!