congrats on getting engaged and i don't want to cramp your style but just try to think past the wedding as THE DAY and think about starting married life- you can have a bloody good wedding day on 10,000 euro which all going well you will have saved up - 10,000 euro will still give you a massive party for your family and friends especially if you start shopping now, without compromising your day.
then you can start married life with a clean slate and no debt hanging over your head. just think how fantastic the two of you will feel to wake up the day AFTER the wedding with no debt in your life. in this day and age thats not a luxury many people have and you can have it as you've been good savers.
- there is alot of paying back on 21, 000 with interest- so you'll be either crippled in repayments to pay it back in 5 yrs or paying loads of interest.
but hey-maybe i'm just being boring and sensible - if you want the massive blow out go for it and have fun !!