As others say, the optimal bet, would include at least two new cards- in which case, definitely not avoiding a double pull. And if Slate is in consideration, where do you fall in with 5/24? So, two new cards, at least a double pull and near-max UTI on said new cards- a lot to consider tanking your score when you currently have low to 0% UTI.
I have, at this moment, only one HP and 1/24 on my files.
30k it is a goal but I'll manage lower CL, if I have to 
I've narrowed my choices:
Discover it®
0% on Purchases for 6 months and 0% on Balance Transfers for 18 months
BankAmericard® credit card
0% on Purchases for 18 billing cycles and 0% on Balance Transfers for 18 billing cycles for balance transfers made in the first 60 days
HSBC Gold Mastercard
0% Introductory APR on credit card purchases and balance transfers for the first 18 months from account opening.
0%* on purchases and balance transfers for 18 billing cycles*
Citibank Simplicity Credit Card
0% on Purchases for 12 months and 0% on Balance Transfers for 21 months
Chase Slate
But my CL with Chase is 12k from reaching 50% of my income
So, in your expert opinion, where should I start to get best chances for highest CL? What will be #2?
I don't have cards from banks listed above (except Chase that is)
i've been looking at the citi cards as well. they have 3 BT card offers
Citi Rewards (15 months) and Citi Double Cash (18 months)
The Citi Simplicity gives you 21 months but it's also 5% fee vs 3% on the previous two cards.
