PacoTaco
500+ Head-Fier
If you are looking at it from a cost perspective, the lowest price I've seen for the T1 is $900. The EL-8 are $699 MSRP and I expect that within a few months you will be able to find used or open box ones for $600 or less.
The T1 is the beyerdynamic open dynamic flagship competing with the sennheiser hd800 and akg k812 pro. Planar flagships include the Audeze LCD-X/LCD-3, Hifiman HE-6/HE-560, and the Oppo PM1.
The EL-8 is a high-end (so luxury mid-fi but under summit-fi) orthodynamic pair of headphones competing (price-wise) with other planar magnetic options like the HE-400i, HE-560, Fostex TH500, Oppo PM1/2, and Mr. Speakers Alpha Dog/Alpha Dog Pro. They are closely priced to some other upper mid-fi dynamic options like the closed TH600.
Audeze also offers the LCD-2 which is quite close to the pricing of the T1 and EL-8, so that is another highly rated classic option to consider.
You should pick based on your sound signature preference. If you don't have a sound signature preference, then you can look into the multitude of other options at similar price points. I am assuming that the EL-8 is the same price as the T1 in Singapore due to mark-up, so from a dollarerformance perspective you may be overpaying a bit for that, but if you love the sound signature, it can be a good investment.
edit: I personally would always go for a flagship offering if budget is not a concern. I prefer planars over dynamics, so I would actually pick the HE-560 or LCD-X from my personal auditioning experience. hahah sorry that is not either of your presented choices.
For your specific choices, I personally would consider the T1 if I was looking between the T1/HD800/K812 pro, but I would pick the K812 pro personally out of those choices followed by the T1 and HD800 (based on personal sound sig preference). For the EL-8, I would choose between closed EL-8 against the Oppo PM-3 (possibly the TH-600s) for high-end closed portable usage or I would consider the open EL-8 vs the LCD-2 or Hifiman HE-400i if going for an upper mid-fi pair of open headphones for home listening due to cost restraints preventing a flagship purchase right now or if looking from a more budget-minded great performance per dollar type perspective. for noise-isolating at home listening, I think the closed el-8 or the closed mr. speaker's alpha dog line-up or the closed audeze xc or the th900 are your only real closed high-end options.
your purchasing decision may be different, but that's how I would look at it!! (if advising independent of sound signature preferences) hope this is helpful
I've seen (and bought) T1s at below $750. Not to diminish your point or anything. Also, never, ever use Th600 or th900 for portable use. They're too fragile and leak sound more than even the T1. Alpha Dogs could work thiugh.