hi gers, i'm dreaming of a nice beach wedding too, but there's really quite limited choices and hard to watch the budget.
well, i've attended the wedding show by 1-twentysix in may, and it was quite an awesome experience. it started ard 4pm by showing you around. and then there is a mock up beach wedding at 6pm, even the cake cutting and toasting, and serve with their buffet spread, they also have a live band playing acoustic, perfecting the ambience as night falls! it'll be a great intimate gathering for friends and close relatives in such settings, otherwise, i think you shouldn't consider if you need a proper sit-down banquet (you know the elders

)
just a rough gauge of the cost, for a dinner buffet it's $12k for 100pax which you can only use the upper part of the area, if you want to extend the lower part to cater for more guests, the cost will be hike up alot. additionally, the beach wedding set up is another cost that will not be included in the package, which may cost ard $3k when i asked them, otherwise, u can always solemnise in one of their 'pavilion' at the area, can be very nicely decorated too. then there is the live band which is sort of in house, if you wanna hire them, it'll be another cost.
if you like those night fall casual bar setting for your celebration, i think it's a really great place to hold it, so it's worth taking a trip down to have a look or ask them when's their next wedding show
as for comparison of rasa sentosa and amara sanctuary, hmm, i haven't seen rasa sentosa new look, but from you gers opinions, i think it's lovely, but after looking at the price haha, amara sanctuary is definitely cheaper than rasa sentosa horizon pavilion
i have also attended amara sanctuary's wedding show before, they have great food there, esp the western style, their dessert buffet is awesome too, maybe can change the chinese menu dessert to this option

but i'm not sure if there is additional cost in having your solemnization at the glass pavilion...
good luck to all in finding your ideal venue! i'm still twisting my brain juice haha