I worked trough the evidence for this old J2a clade for ISOGG certification and found new structure: http://tree.j2-m172.info/?Hg=J2a1b
Z6049 is equivalent to S18476/SK2198. A new subclade is SK1312 for whom so far all Georgian BigY are positive: 270352, 259005, 258936
Since Z6048 has no coverage in BigY we have to wait until FTDNA is able to complete the BigY of 168300 Niederleithner to understand his position better. Tsotne Sharabidze has announced that YFull-Analysis will be done on the Georgian BigY. If they join the J2a group that will be useful to find subclades of them. Obviously it would be also interesting to have the BigY of 289702 Naparstek and E10625 Akhvlediani to understand their position in the tree.
UPDATE 31 March 2015: finished the analysis of the available Z6049 data including Abkhazian EstonianBiocentre sample: EB-14410 Georgia and 259005/YF03085 Georgia are SK1317,SK1318 and share 53 of the 82 personal YFS SNPs of YF03085.
1 April: HGDP01403 Adygei is SK1321+ SK1317+ SK1320+