The option of electrum will be better since it shall take few minutes to get everything setup and people shall receive their payment.
How secure is electrum wallet? What are the transaction fees for send btc on their network ?
Bitcoin Core is definitely better in terms of security and privacy but the tradeoff is worth it for the convenience.
All your private keys are stored within the Electrum wallet and as long as you download it from their official website and the signature matches, it is very secure. They do not have any control over your private key.
For the transaction fees, you can set your own fee for the entire transaction, per kb or use dynamic fee which adjusts the fee structure automatically. I would recommend the latter though it can costs more but at least it will get confirmed in a fairly reasonable time.
I just wanted to add one last thing: it seems like you (the OP), are a bit confused on the topic of fees.
Electrum doesn't charge any fees* to send BTC on their network, neither does core, neither does blockchain.info (as far as i know).
There is one network, different wallet clients that help you keeping track of your outputs, create transactions, sign messages,... All these wallets should use the same network, the same ledger, the same protocol,... (unless you're talking about altcoins)
YOU use unspent outputs as input for a new transaction, the difference between the sum of the inputs and sum of the outputs is the fee. The fee is payed to the miner that mines the block that includes your transaction. The higher the fee per byte of transaction data, the better the odds will be that a miner will pick your transaction to be added to the block he's currently working on.
Altough some wallets have a built-in security, there are a lot of wallets that will allow you to create 0 fee transactions, but your chances of getting those ones in a block are very small.
There also used to be some wallets that did charge a fee (like the old multibit HD), but i think most of them have stopped this practice.
* PS: electrum works together with a 2FA provider that does charge a fee, so if you enable 2FA in electrum, you might have to pay a per-transaction fee (afaik)