I get the info from measuring my feet without socks on, have actually demoed 7.5EE Supremes (length was good, but had a bit of heel lift in the EE and the D forfoot was too narrow so they weren't perfect) on a few times at Modsquad events and tried on a pair of 8.5 Alkali's. I also use 8.5 KOR skates and according to the KOR fit guide an 8.5 skate is 26.9cm - my very wide 26.7cm foot brushes the toe caps on those skates with thin socks on so that would confirm the length. I do like to wear skates as small as possible without serious pain and have my toes brushing the caps. Some people go longer than they need to allow for a wide foot instead of going down in length and using a wider size/skate. I don't know how wide your feet are in comparison to the length so don't know if that's the case for you. Nothing beats trying the skates on, but if you've measured accurately and your foot is 26cm then my best guess from my experiences are you'd need a 7 Supreme and 7.5 Alkali for that brushing the toe fit - if you like extra room (which you seem to) then a 7.5 Supreme and 8 Alkali would provide that room. Your 8.5 Supremes might not feel like they're at least 1 size too long because you may tie them tight and/or have a wider foot so it feel secure in a D boot. If you went down a size or size and a half and do have a wider foot then you might need to go with a wider size. Your feet being a little off the cap in 8.5 Alkali's is actually consistent with my experience since my feet are almost the same size. The 8.5 Alkali's that I tried on were almost the right size and my feet were just off the cap so I felt that 8s would lengthwise (don't know if they'd be wide enough for my flippers), but there were no 8s to try on - I prefer my big toe to be touching the cap at first and then just brushing the cap after the skates are baked and broken in. That's just a fit preference.